Method to manage downlink data delivery status

ABSTRACT

The generation and use of a modified DDDS, suitable for RLC AM and RLC UM, is disclosed herein. The modified DDDS optionally includes an IE specifying a highest sequence number of a packet successfully delivered to a wireless terminal. Node B, which is in wireless communication with a wireless terminal, sends the modified DDDS to Node A, where Node A sends DL data packets to Node B for transmission to the wireless terminal responsive to the received modified DDDS.

RELATED APPLICATIONS

This application is a 371 of International Application No.PCT/IB2018/057462, filed Sep. 26, 2018, which claims priority to U.S.Provisional Application Ser. No. 62/563,852, filed Sep. 27, 2017, thedisclosures of which are incorporated in their entirety by reference.

TECHNICAL FIELD

The solution presented herein generally relates to controlling thedelivery of downlink data packets, and more particularly relates to theDownlink Data Delivery Status (DDDS) used to implement such control.

BACKGROUND

Generally, all terms used herein are to be interpreted according totheir ordinary meaning in the relevant technical field, unless adifferent meaning is clearly given and/or is implied from the context inwhich it is used. All references to a/an/the element, apparatus,component, means, step, etc. are to be interpreted openly as referringto at least one instance of the element, apparatus, component, means,step, etc., unless explicitly stated otherwise. The steps of any methodsdisclosed herein do not have to be performed in the exact orderdisclosed, unless a step is explicitly described as following orpreceding another step and/or where it is implicit that a step mustfollow or precede another step. Any feature of any of the embodimentsdisclosed herein may be applied to any other embodiment, whereverappropriate. Likewise, any advantage of any of the embodiments may applyto any other embodiments, and vice versa. Other objectives, features andadvantages of the enclosed embodiments will be apparent from thefollowing description.

Dual connectivity is a 3rd Generation Partnership Project (3GPP) Release12 feature where radio resources from two eNBs are aggregated, and aUser Equipment (UE) is connected to the two eNBs simultaneously. Toassist the user plan data distribution, Downlink Data Delivery Status(DDDS) was introduced to provide feedback to allow the node hostingPacket Data Convergence Protocol (PDCP) entity to control the downlinkuser data flow.

When 3GPP Release 15 introduces 5G/New Radio (NR), the dual connectivitythen is expected to expand to cover dual connectivity between a LongTerm Evolution (LTE) node and an NR node, or between two NR nodes. See,e.g., FIG. 6, which shows an example of Dual Connectivity in NR.

With the introduction of splitting the Next Generation Radio AccessNetwork (NG-RAN) node into a Central Unit (CU) and a Distributed Unit(DU), a user plane protocol is also introduced in the 5G NG-RAN node.Consequently, the DDDS is included in the following user planeprotocols: X2 interface user plane protocol (X2UP), Xn interface userplane protocol (XnUP), and F1 interface user plane protocol (F1UP).

The conventional DDDS includes the following three mandatory informationelements (IEs):

-   -   the highest PDCP Protocol Data Unit (PDU) sequence number (SN)        successfully delivered in sequence to the UE among those PDCP        PDUs received from the NG-RAN node (e.g., gNB) hosting the PDCP        entity;    -   the desired buffer size in bytes for the concerned data bearer;        and    -   the minimum desired buffer size in bytes for the UE.

The desired buffer size is defined as “information of the currentlydesired buffer size at the Secondary eNB (SeNB) for transmitting to theUE user data associated with a specific E-RAB (E-UTRAN (UniversalTerrestrial Radio Access Network) Radio Access Bearer) configured withthe split bearer option.”

This restricts the use of the DDDS and makes it impossible in the caseswhen we want to better utilize the message.

There currently exist certain challenges. As indicated above, one of themandatory presented information elements in LTE DDDS is “the highestPDCP PDU sequence number successfully delivered in sequence to the UE.”First, this implies that the DDDS is meant only for the Radio LinkControl Acknowledged Mode (RLC AM), where the system could feedback thePDCP PDUs successfully delivered and acknowledged by the UE. Second,this implies that the DDDS sending frequency is determined by the RLCAcked rate, which is the rate/frequency at which the RLC layer sends theAcknowledgement. It is beneficial to be able to use the DDDS for RLCUnacknowledged Mode (UM) user data flow control.

Another drawback is that it is not possible to send the DDDS before thefirst RLC sends an ACK message. Sending the DDDS in advance may bebeneficial for the assisting node (e.g., SeNB or S-NG-RAN node) toinform the node hosting the PDCP entity (e.g., MeNB or M-NG-RAN node)the desired buffer size so that the node hosting the PDCP entity coulddistribute the data packages accordingly.

Lastly it is not possible to use DDDS for the purpose of only providingthe information of the desired buffer size and the minimum desiredbuffer size during the data transmission, without repeating the “thehighest PDCP PDU sequence number successfully delivered,” when it isunchanged.

SUMMARY

Certain aspects of the present disclosure and their embodiments mayprovide solutions to these or other challenges. According to certainembodiments, a solution to solve the above-mentioned problems is toenhance the current DDDS. These enhancements could include, withoutlimitation, one or more of the following:

-   -   Only include “the highest PDCP PDU sequence number successfully        delivered in sequence to the UE among those PDCP PDUs received        from the gNB hosting the PDCP entity” when it applies, e.g.,        making this information element as optionally present;    -   Extend the desired buffer size to cover the case for RLC UM;    -   Either modify or introduce a IE to cover the flow control for        RLC UM, and also make it optionally present.

These solutions could apply on XnUP, F1UP, and X2UP interface protocol.According to certain embodiments, the enhanced DDDS is sent any time theassisting node desires, and it applies both for RLC UM and RLC AM modes.

There are, proposed herein, various embodiments which address one ormore of the issues disclosed herein. Certain of these embodiments mayprovide one or more of the following technical advantages. According tocertain embodiments, the user plan flow control downlink data deliverystatus can be used to feedback to the node hosting PDCP entity thedesired buffer size related information only, reducing transmission ofunnecessary information. According to certain embodiments, the solutionsmay also be used for RLC UM flow control. Certain embodiments mayprovide all, some, or none of these technical advantages. These andother technical advantages may be readily apparent and will be describedin more detail below.

One exemplary embodiment comprises a method, implemented by a firstnetwork node (Node B), of reporting a Downlink Data Delivery Status(DDDS) for a wireless terminal from the first network node (Node B) to asecond network node (Node A). The method comprises generating a DDDSframe comprising a first indicator and at least a first InformationElement (IE) specifying a desired buffer size for a data bearer and/or aminimum desired buffer size for the wireless terminal. The methodfurther comprises determining whether to include a second IE in the DDDSframe, where the second IE specifies a highest sequence number for apacket successfully delivered to the wireless terminal. The methodfurther comprises setting a value of the first status indicatorresponsive to the determining whether to include the second IE in theDDDS frame to indicate a presence and/or an absence of the second IE inthe DDDS frame. The method further comprises adding the second IE to theDDDS frame when the first status indicator indicates the presence of thesecond IE in the DDDS frame, and sending the DDDS frame to the secondnetwork node (Node A) to facilitate control, by the second network node(Node A), of downlink data flow to the wireless terminal.

Another exemplary embodiment comprises a computer program product forcontrolling a first network node (Node B). The computer program productcomprises software instructions which, when run on at least oneprocessing circuit in the first network node (Node B), causes the firstnetwork node (Node B) to execute a method of reporting a Downlink DataDelivery Status (DDDS) for a wireless terminal from the first networknode (Node B) to a second network node (Node A). When run on theprocessing circuit, the software instructions cause the first networknode (Node B) to generate a DDDS frame comprising a first indicator andat least a first Information Element (IE) specifying a desired buffersize for a data bearer and/or a minimum desired buffer size for thewireless terminal. When run on the processing circuit, the softwareinstructions further cause the first network node (Node B) to determinewhether to include a second IE in the DDDS frame, where the second IEspecifies a highest sequence number for a packet successfully deliveredto the wireless terminal. When run on the processing circuit, thesoftware instructions further cause the first network node (Node B) toset a value of the first status indicator responsive to the determiningwhether to include the second IE in the DDDS frame to indicate apresence and/or an absence of the second IE in the DDDS frame. When runon the processing circuit, the software instructions further cause thefirst network node (Node B) to add the second IE to the DDDS frame whenthe first status indicator indicates the presence of the second IE inthe DDDS frame, and send the DDDS frame to the second network node (NodeA) to facilitate control, by the second network node (Node A), ofdownlink data flow to the wireless terminal. In one exemplaryembodiment, a computer-readable medium comprises the computer programproduct. In one exemplary embodiment, the computer-readable medium maycomprise a non-transitory computer-readable medium.

Another exemplary embodiment comprises a first network node (Node B)configured to report a Downlink Data Delivery Status (DDDS) for awireless terminal to a second network node (Node A). The first networknode (Node B) comprises one or more processing circuits and acommunication circuit. The one or more processing circuits areconfigured to generate a DDDS frame comprising a first status indicatorand at least a first Information Element (IE) specifying a desiredbuffer size for a data bearer and/or a minimum desired buffer size forthe wireless terminal. The one or more processing circuits are furtherconfigured to determine whether to include a second IE in the DDDSframe, where the second IE specifies a highest sequence number for apacket successfully delivered to the wireless terminal. The one or moreprocessing circuits are further configured to set a value of the firststatus indicator responsive to the determining to indicate a presenceand/or an absence of the second IE in the DDDS frame, and to add thesecond IE to the DDDS frame when the first status indicator indicatesthe presence of the second IE in the DDDS frame. The communicationcircuit is configured to send the DDDS frame to the second network node(Node A) to facilitate control, by the second network node (Node A), ofdownlink data flow to the wireless terminal.

Another exemplary embodiment comprises a first network node (Node B)configured to report a Downlink Data Delivery Status (DDDS) for awireless terminal to a second network node (Node A). The first networknode (Node B) is configured to generate a DDDS frame comprising a firststatus indicator and at least a first Information Element (IE)specifying a desired buffer size for a data bearer and/or a minimumdesired buffer size for the wireless terminal. The first network node(Node B) is further configured to determine whether to include a secondIE in the DDDS frame, where the second IE specifies a highest sequencenumber fora packet successfully delivered to the wireless terminal. Thefirst network node (Node B) is further configured to set a value of thefirst status indicator responsive to the determining to indicate apresence and/or an absence of the second IE in the DDDS frame, and addthe second IE to the DDDS frame when the first status indicatorindicates the presence of the second IE in the DDDS frame. The firstnetwork node (Node B) is further configured to send the DDDS frame tothe second network node (Node A) to facilitate control, by the secondnetwork node (Node A), of downlink data flow to the wireless terminal.

Another exemplary embodiment comprises a method, implemented by a firstnetwork node (Node A) of controlling downlink data flow from the firstnetwork node (Node A) to a wireless terminal. The method comprisesreceiving, from a second network node (Node B), a Downlink Data DeliveryStatus (DDDS) frame comprising at least a first Information Element (IE)and a first status indicator. The method further comprises determining adesired buffer size for a data bearer and/or a minimum desired buffersize for the wireless terminal from the first IE in the DDDS frame. Themethod further comprises controlling the downlink data flow from thefirst network node (Node A) to the wireless terminal responsive to thedetermined desired buffer size for the data bearer and/or the determinedminimum desired buffer size for the wireless terminal. The methodfurther comprises evaluating the first status indicator in the DDDSframe to determine whether the DDDS frame includes a second IE. When thefirst status indicator indicates the DDDS frame includes the second IE,the method further comprises determining a highest sequence number for apacket successfully delivered by the first network node (Node A) to thewireless terminal from the second IE, and further controlling thedownlink data flow from the first network node (Node A) to the wirelessterminal responsive to the determined highest sequence number. Themethod further comprises sending downlink data to the wireless terminalaccording to the downlink data flow.

Another exemplary embodiment comprises a computer program product forcontrolling a first network node (Node A). The computer program productcomprises software instructions which, when run on at least oneprocessing circuit in the first network node (Node A), causes the firstnetwork node (Node A) to control downlink data flow from the firstnetwork node (Node A) to a wireless terminal. When run on the processingcircuit, the software instructions cause the first network node (Node A)to receive, from a second network node (Node B), a Downlink DataDelivery Status (DDDS) frame comprising at least a first InformationElement (IE) and a first status indicator. When run on the processingcircuit, the software instructions further cause the first network node(Node A) to determine a desired buffer size for a data bearer and/or aminimum desired buffer size for the wireless terminal from the first IEin the DDDS frame. When run on the processing circuit, the softwareinstructions further cause the first network node (Node A) to controlthe downlink data flow from the first network node (Node A) to thewireless terminal responsive to the determined desired buffer size forthe data bearer and/or the determined minimum desired buffer size forthe wireless terminal. When run on the processing circuit, the softwareinstructions further cause the first network node (Node A) to evaluatethe first status indicator in the DDDS frame to determine whether theDDDS frame includes a second IE. When the first status indicatorindicates the DDDS frame includes the second IE, the softwareinstruction further cause the first network node to determine a highestsequence number for a packet successfully delivered by the first networknode (Node A) to the wireless terminal from the second IE, and tofurther control the downlink data flow from the first network node (NodeA) to the wireless terminal responsive to the determined highestsequence number. When run on the processing circuit, the softwareinstructions further cause the first network node (Node A) to senddownlink data to the wireless terminal according to the downlink dataflow. In one exemplary embodiment, a computer-readable medium comprisesthe computer program product. In one exemplary embodiment, thecomputer-readable medium comprises a non-transitory computer-readablemedium.

Another exemplary embodiment comprises a first network node (Node A)configured to control downlink data flow to a wireless terminal. Thefirst network node (Node A) comprises a communication circuit and one ormore processing circuits. The communication circuit is configured toreceive, from a second network node (Node B), a Downlink Data DeliveryStatus (DDDS) frame comprising at least a first Information Element (IE)and a first status indicator. The one or more processing circuits areconfigured to determine a desired buffer size for the data bearer and/ora minimum desired buffer size for the wireless terminal from the firstIE in the DDDS frame. The one or more processing circuits are furtherconfigured to control the downlink data flow from the first network node(Node A) to the wireless terminal responsive to the determined desiredbuffer size for the data bearer and/or the determined minimum desiredbuffer size for the wireless terminal. The one or more processingcircuits are further configured to evaluate the first status indicatorin the DDDS frame to determine whether the DDDS frame includes a secondIE. When the first status indicator indicates the DDDS frame includesthe second IE, the one or more processing circuits are configured todetermine a highest sequence number for a packet successfully deliveredby the first network node (Node A) to the wireless terminal from thesecond IE, and further control the downlink data flow from the firstnetwork node (Node A) responsive to the determined highest sequencenumber. The communication circuit is further configured to send downlinkdata to the wireless terminal according to the downlink data flow.

Another exemplary embodiment comprises a first network node (Node A) forcontrolling downlink data flow from the first network node (Node A) to awireless terminal. The first network node (Node A) is configured toreceive, from a second network node (Node B), a Downlink Data DeliveryStatus (DDDS) frame comprising at least a first Information Element (IE)and a first status indicator. The first network node (Node A) is furtherconfigured to determine a desired buffer size for the data bearer and/ora minimum desired buffer size for the wireless terminal from the firstIE in the DDDS frame. The first network node (Node A) is furtherconfigured to control the downlink data flow from the first network node(Node A) to the wireless terminal responsive to the determined desiredbuffer size for the data bearer and/or the determined minimum desiredbuffer size for the wireless terminal. The first network node (Node A)is further configured to evaluate the first status indicator in the DDDSframe to determine whether the DDDS frame includes a second IE. When thefirst status indicator indicates the DDDS frame includes the second IE,the first network node (Node A) is further configured to determine ahighest sequence number for a packet successfully delivered by the firstnetwork node (Node A) to the wireless terminal from the second IE, andto further control the downlink data flow from the first network node(Node A) responsive to the determined highest sequence number. The firstnetwork node (Node A) is further configured to send downlink data to thewireless terminal according to the downlink data flow.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an exemplary wireless network according to exemplaryembodiments of the solution presented herein.

FIG. 2 shows a method for providing a DDDS frame from Node B to Node Aaccording to exemplary embodiments of the solution presented herein.

FIG. 3 shows a method for determining a data flow from a received DDDSframe, and providing data to the wireless terminal according toexemplary embodiments of the solution presented herein.

FIG. 4 shows a block diagram for an exemplary wireless terminalaccording to exemplary embodiments of the solution presented herein.

FIG. 5 shows a block diagram for an exemplary network node according toexemplary embodiments of the solution presented herein.

FIG. 6 shows an example of Dual Connectivity in New Radio.

FIG. 7A shows an exemplary DDDS frame according to exemplary embodimentsof the solution presented herein.

FIG. 7B shows another exemplary DDDS frame according to exemplaryembodiments of the solution presented herein.

FIG. 7C shows another exemplary DDDS frame according to exemplaryembodiments of the solution presented herein.

FIG. 8 shows an exemplary wireless network applicable to the solutionpresented herein.

FIG. 9 shows an exemplary UE applicable to the solution presentedherein.

FIG. 10 shows an exemplary virtualization environment applicable to thesolution presented herein.

FIG. 11 shows an exemplary telecommunications network applicable to thesolution presented herein.

FIG. 12 shows an exemplary host computer applicable to the solutionpresented herein.

FIG. 13 shows an exemplary method implemented in a communication systemin accordance with embodiments of the solution presented herein.

FIG. 14 shows another exemplary method implemented in a communicationsystem in accordance with embodiments of the solution presented herein.

FIG. 15 shows another exemplary method implemented in a communicationsystem in accordance with embodiments of the solution presented herein.

FIG. 16 shows another exemplary method implemented in a communicationsystem in accordance with embodiments of the solution presented herein.

DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be described morefully with reference to the accompanying drawings. Other embodiments,however, are contained within the scope of the subject matter disclosedherein, and the disclosed subject matter should not be construed aslimited to only the embodiments set forth herein; rather, theseembodiments are provided by way of example to convey the scope of thesubject matter to those skilled in the art. Additional information mayalso be found in the documents provided in the Appendix.

FIG. 1 shows an exemplary wireless network 10 comprising a Network NodeA 12, a Network Node B 14, and a wireless terminal 16. Node B 14 sends aDownlink Data Delivery Status (DDDS) to Node A 12. Node A 12 uses thereceived DDDS to control the delivery of downlink data from Node A 12 tothe wireless terminal 16 via Node B 14.

FIG. 2 shows an exemplary method of reporting the DDDS for the wirelessterminal 16 from Node B 14 to Node A 12, where the method is implementedby Node B 14. The method comprises generating a DDDS frame comprising afirst indicator and at least a first Information Element (IE) specifyinga desired buffer size for a data bearer and/or a minimum desired buffersize for the wireless terminal 16 (Block 100). The method furthercomprises determining whether to include a second IE in the DDDS frame(Block 110), where the second IE specifies a highest sequence number fora packet successfully delivered to the wireless terminal. The methodfurther comprises setting a value of the first status indicatorresponsive to the determining whether to include the second IE in theDDDS frame to indicate a presence and/or an absence of the second IE inthe DDDS frame (Block 120, Block 140). The method further comprisesadding the second IE to the DDDS frame (Block 130) when the first statusindicator indicates the presence of the second IE in the DDDS frame(Block 120), and sending the DDDS frame to Node A 12 to facilitatecontrol, by Node A 12, of downlink data flow to the wireless terminal 16(Block 150).

FIG. 3 shows an exemplary method, implemented by Node A 12, ofcontrolling downlink data flow from Node A 12 to the wireless terminal16. The method comprises receiving, from Node B 14, a DDDS framecomprising at least a first Information Element (IE) and a first statusindicator (Block 200). The method further comprises determining adesired buffer size for a data bearer and/or a minimum desired buffersize for the wireless terminal 16 from the first IE in the DDDS frame(Block 210). The method further comprises controlling the downlink dataflow from Node A 12 to the wireless terminal 16 responsive to thedetermined desired buffer size for the data bearer and/or the determinedminimum desired buffer size for the wireless terminal 16 (Block 220).The method further comprises evaluating the first status indicator inthe DDDS frame to determine whether the DDDS frame includes a second IE(Block 230). When the first status indicator indicates the DDDS frameincludes the second IE, the method further comprises determining ahighest sequence number for a packet successfully delivered by Node A 12to the wireless terminal 16 from the second IE (Block 240), and furthercontrolling the downlink data flow from Node A 12 to the wirelessterminal 16 responsive to the determined highest sequence number (Block250). The method further comprises sending downlink data to the wirelessterminal 16 according to the downlink data flow (Block 260).

FIG. 4 shows a block diagram for an exemplary wireless terminal 300,which corresponds to the wireless terminal 16 in FIG. 1. The wirelessterminal 300 comprises one or more processing circuits 310 that controlthe operation of the wireless terminal 300 according to at least theinstructions stored in memory 330. The wireless terminal 300 furthercomprises communication circuit 320 configured to transmit and/orreceive wireless signals in the wireless network, e.g., to/from Node B14.

FIG. 5 shows a block diagram for an exemplary network node 400, whichcorresponds to either or both of Node A 12 and Node B of FIG. 1. Thenetwork node 400 comprises a one or more processing circuits 410,communication circuit 420, and memory 430. The one or more processingcircuits 310 control the operation of the network node 400 according toat least the instructions stored in memory 430. The communicationcircuit 420 is configured to transmit and/or receive signals in thewireless network, e.g., to/from other network nodes 400 and/or to/fromthe wireless terminal 16.

When network node 400 comprises Node A 12, the communication circuit 420is configured to receive, from another network node, e.g., Node B 14, aDDDS frame comprising at least a first IE and a first status indicator.The one or more processing circuits 410 are configured to determine adesired buffer size for the data bearer and/or a minimum desired buffersize for the wireless terminal 16 from the first IE in the DDDS frame.The one or more processing circuits 410 are further configured tocontrol the downlink data flow from Node A 12 to the wireless terminal16 responsive to the determined desired buffer size for the data bearerand/or the determined minimum desired buffer size for the wirelessterminal. The one or more processing circuits 410 are further configuredto evaluate the first status indicator in the DDDS frame to determinewhether the DDDS frame includes a second IE. When the first statusindicator indicates the DDDS frame includes the second IE, the one ormore processing circuits are configured to determine a highest sequencenumber for a packet successfully delivered by Node A 12 to the wirelessterminal 16 from the second IE, and further control the downlink dataflow from Node A 12 responsive to the determined highest sequencenumber. The communication circuit 420 is further configured to senddownlink data to the wireless terminal 16 according to the downlink dataflow.

When the network node 400 comprises Node B 14, the one or moreprocessing circuits 410 are configured to generate a DDDS framecomprising a first status indicator and at least a first InformationElement (IE) specifying a desired buffer size for a data bearer and/or aminimum desired buffer size for the wireless terminal 16. The one ormore processing circuits 410 are further configured to determine whetherto include a second IE in the DDDS frame, where the second IE specifiesa highest sequence number for a packet successfully delivered to thewireless terminal 16. The one or more processing circuits 410 arefurther configured to set a value of the first status indicatorresponsive to the determining to indicate a presence and/or an absenceof the second IE in the DDDS frame, and to add the second IE to the DDDSframe when the first status indicator indicates the presence of thesecond IE in the DDDS frame. The communication circuit 420 is configuredto send the DDDS frame to Node A 12 to facilitate control, by Node A 12,of downlink data flow to the wireless terminal 16.

To ensure the DDDS can be sent only containing the desired buffer sizerelated information (for example before the data delivery), according tocertain embodiments the mandatory presented IE “the highest PDCP PDUsequence number successfully delivered in sequence to the UE among thosePDCP PDUs received from the gNB hosting the PDCP entity” is modified tobe optional. A new indication is introduced to indicate the presence ofthis IE. For example, one way to implement the solution presented hereinis to allocate one of the spare bits and define an indication, as shownin FIG. 7A and in Table 1. In the example of FIG. 7A, the “Highest PDCPDelivered Ind” is introduced to indicate the presence of the “Highestsuccessfully delivered PDCP Sequence Number” IE.

TABLE 1 Highest PDCP Delivered Indication Description: This parameterindicates the presence of the Highest successfully delivered PDCPSequence Number. Value range: {0 = Highest successfully delivered PDCPSequence Number not present, 1 = Highest successfully delivered PDCPSequence Number present}.

According to certain embodiments, an alternative solution could be thatan indication is introduced by using the existing spare bits to saywhether the PDCP PDU SN information is new or just a repetition, e.g.,the same as last signaled, in which case the PDCP PDU SN is notpresented.

According to certain embodiments, an alternative solution could be thatan indication is introduced by using the existing spare bits to say thatthe PDCP PDU SN information can be ignored, e.g., when the indication isset, the PDCP PDU presented is dummy and not used, as shown in refer toFIG. 7B. In the example of FIG. 7B, the “Highest PDCP DeliveredRelevant” is introduced to indicate if the “Highest successfullydelivered PDCP Sequence Number” IE is relevant or not. When thisIndication is set (e.g., to 1), the Highest successfully delivered PDCPSequence Number could be a dummy value.

As X2UP is already standardized (see 3GPP TS 36.425), the introductionof the above presence indication should be made in a manner that isbackwards compatible, for example, when using the spare bit, use value 0to indicate the IE is present, and value 1 to indicate the IE is notpresent, due to the fact that the spare bits are set to 0.

For RLC UM flow control, it is sufficient to get feedbacks on what hadbeen transmitted to the lower layer (e.g., Medium Access Control (MAC)layer). To make the DDDS applicable for RLC UM mode flow control, thedefinition of the “desired buffer size” and the “minimum desired buffersize” needs to be extended, to clearly state it is the desired buffersize to be transmitted to the MAC layer, in order to cover the RLC UMmode. One non-limiting example of this is shown in Table 2, althoughother specific implementations may also be possible. In particular,Table 2 shows an example of extending the desired buffer size to clearstate the case of transmitting to MAC layer, to cover the RLC UM mode.

TABLE 2 Information of the currently desired buffer size at the SgNB fortransmitting to the UE user data or MAC layer associated with a specificdata bearer configured with the split bearer option; Information of thecurrently minimum desired buffer size at the SgNB for transmitting tothe UE user data or MAC layer associated with all data bearersconfigured with the split bearer option.

The highest transmitted PDCP Sequence Number can be introduced to beused both for RLC UM and RLC AM mode. It is meant to indicate thehighest PDCP SN that has been requested by MAC layer for transmissionover the Uu interface. When it is used for RLC AM mode, it should not beused by the node hosting the PDCP entity to remove the PDCP PDU,however. This information element should also be introduced asoptionally present. An indication is introduced to indicate the presenceof this IE. One non-limiting example is shown in FIG. 7C and Table 3,although other specific implementations may also be possible.

TABLE 3 Highest PDCP Transmitted Indication Description: This parameterindicates the presence of the Highest transmitted PDCP Sequence Number.Value range: {0 = Highest transmitted PDCP Sequence Number not present,1 = Highest transmitted PDCP Sequence Number present}. Field length: 1bit.

The solution may apply for X2UP, XnUP and F1UP. The indications andinformation elements may be introduced in different places or withdifferent names.

As discussed herein, the proposed solutions may be performed by variousnetwork nodes and UEs operating in a dual connectivity setting. Thesenodes and UEs, as well as the network they operate in, will now bedescribed in more detail.

Although the subject matter described herein may be implemented in anyappropriate type of system using any suitable components, theembodiments disclosed herein are described in relation to a wirelessnetwork, such as the example wireless network illustrated in FIG. 8. Forsimplicity, the wireless network of FIG. 8 only depicts network 806,network nodes 860 and 860 b, and WDs 810, 810 b, and 810 c. In practice,a wireless network may further include any additional elements suitableto support communication between wireless devices or between a wirelessdevice and another communication device, such as a landline telephone, aservice provider, or any other network node or end device. Of theillustrated components, network node 860 and wireless device (WD) 810are depicted with additional detail. The wireless network may providecommunication and other types of services to one or more wirelessdevices to facilitate the wireless devices' access to and/or use of theservices provided by, or via, the wireless network.

The wireless network may comprise and/or interface with any type ofcommunication, telecommunication, data, cellular, and/or radio networkor other similar type of system. In some embodiments, the wirelessnetwork may be configured to operate according to specific standards orother types of predefined rules or procedures. Thus, particularembodiments of the wireless network may implement communicationstandards, such as Global System for Mobile Communications (GSM),Universal Mobile Telecommunications System (UMTS), Long Term Evolution(LTE), and/or other suitable 2G, 3G, 4G, or 5G standards; wireless localarea network (WLAN) standards, such as the IEEE 802.11 standards; and/orany other appropriate wireless communication standard, such as theWorldwide Interoperability for Microwave Access (WiMax), Bluetooth,Z-Wave and/or ZigBee standards.

Network 806 may comprise one or more backhaul networks, core networks,IP networks, public switched telephone networks (PSTNs), packet datanetworks, optical networks, wide-area networks (WANs), local areanetworks (LANs), wireless local area networks (WLANs), wired networks,wireless networks, metropolitan area networks, and other networks toenable communication between devices.

Network node 860 and WD 810 comprise various components described inmore detail below. These components work together in order to providenetwork node and/or wireless device functionality, such as providingwireless connections in a wireless network. In different embodiments,the wireless network may comprise any number of wired or wirelessnetworks, network nodes, base stations, controllers, wireless devices,relay stations, and/or any other components or systems that mayfacilitate or participate in the communication of data and/or signalswhether via wired or wireless connections.

As used herein, network node refers to equipment capable, configured,arranged and/or operable to communicate directly or indirectly with awireless device and/or with other network nodes or equipment in thewireless network to enable and/or provide wireless access to thewireless device and/or to perform other functions (e.g., administration)in the wireless network. Examples of network nodes include, but are notlimited to, access points (APs) (e.g., radio access points), basestations (BSs) (e.g., radio base stations, Node Bs, and evolved Node Bs(eNBs)). Base stations may be categorized based on the amount ofcoverage they provide (or, stated differently, their transmit powerlevel) and may then also be referred to as femto base stations, picobase stations, micro base stations, or macro base stations. A basestation may be a relay node or a relay donor node controlling a relay. Anetwork node may also include one or more (or all) parts of adistributed radio base station such as centralized digital units and/orremote radio units (RRUs), sometimes referred to as Remote Radio Heads(RRHs). Such remote radio units may or may not be integrated with anantenna as an antenna integrated radio. Parts of a distributed radiobase station may also be referred to as nodes in a distributed antennasystem (DAS). Yet further examples of network nodes includemulti-standard radio (MSR) equipment such as MSR BSs, networkcontrollers such as radio network controllers (RNCs) or base stationcontrollers (BSCs), base transceiver stations (BTSs), transmissionpoints, transmission nodes, multi-cell/multicast coordination entities(MCEs), core network nodes (e.g., MSCs, MMEs), O&M nodes, OSS nodes, SONnodes, positioning nodes (e.g., E-SMLCs), and/or MDTs. As anotherexample, a network node may be a virtual network node as described inmore detail below. More generally, however, network nodes may representany suitable device (or group of devices) capable, configured, arranged,and/or operable to enable and/or provide a wireless device with accessto the wireless network or to provide some service to a wireless devicethat has accessed the wireless network.

In FIG. 8, network node 860 includes processing circuitry 870, devicereadable medium 880, interface 890, auxiliary equipment 884, powersource 886, power circuitry 887, and antenna 862. Although network node860 illustrated in the example wireless network of FIG. 8 may representa device that includes the illustrated combination of hardwarecomponents, other embodiments may comprise network nodes with differentcombinations of components. It is to be understood that a network nodecomprises any suitable combination of hardware and/or software needed toperform the tasks, features, functions and methods disclosed herein.Moreover, while the components of network node 860 are depicted assingle boxes located within a larger box, or nested within multipleboxes, in practice, a network node may comprise multiple differentphysical components that make up a single illustrated component (e.g.,device readable medium 880 may comprise multiple separate hard drives aswell as multiple RAM modules).

Similarly, network node 860 may be composed of multiple physicallyseparate components (e.g., a NodeB component and a RNC component, or aBTS component and a BSC component, etc.), which may each have their ownrespective components. In certain scenarios in which network node 860comprises multiple separate components (e.g., BTS and BSC components),one or more of the separate components may be shared among severalnetwork nodes. For example, a single RNC may control multiple NodeB's.In such a scenario, each unique NodeB and RNC pair, may in someinstances be considered a single separate network node. In someembodiments, network node 860 may be configured to support multipleradio access technologies (RATs). In such embodiments, some componentsmay be duplicated (e.g., separate device readable medium 880 for thedifferent RATs) and some components may be reused (e.g., the sameantenna 862 may be shared by the RATs). Network node 860 may alsoinclude multiple sets of the various illustrated components fordifferent wireless technologies integrated into network node 860, suchas, for example, GSM, WCDMA, LTE, NR, WiFi, or Bluetooth wirelesstechnologies. These wireless technologies may be integrated into thesame or different chip or set of chips and other components withinnetwork node 860.

Processing circuitry 870 is configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being provided by a network node. These operationsperformed by processing circuitry 870 may include processing informationobtained by processing circuitry 870 by, for example, converting theobtained information into other information, comparing the obtainedinformation or converted information to information stored in thenetwork node, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Processing circuitry 870 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software and/or encoded logicoperable to provide, either alone or in conjunction with other networknode 860 components, such as device readable medium 880, network node860 functionality. For example, processing circuitry 870 may executeinstructions stored in device readable medium 880 or in memory withinprocessing circuitry 870. Such functionality may include providing anyof the various wireless features, functions, or benefits discussedherein. In some embodiments, processing circuitry 870 may include asystem on a chip (SOC).

In some embodiments, processing circuitry 870 may include one or more ofradio frequency (RF) transceiver circuitry 872 and baseband processingcircuitry 874. In some embodiments, radio frequency (RF) transceivercircuitry 872 and baseband processing circuitry 874 may be on separatechips (or sets of chips), boards, or units, such as radio units anddigital units. In alternative embodiments, part or all of RF transceivercircuitry 872 and baseband processing circuitry 874 may be on the samechip or set of chips, boards, or units

In certain embodiments, some or all of the functionality describedherein as being provided by a network node, base station, eNB or othersuch network device may be performed by processing circuitry 870executing instructions stored on device readable medium 880 or memorywithin processing circuitry 870. In alternative embodiments, some or allof the functionality may be provided by processing circuitry 870 withoutexecuting instructions stored on a separate or discrete device readablemedium, such as in a hard-wired manner. In any of those embodiments,whether executing instructions stored on a device readable storagemedium or not, processing circuitry 870 can be configured to perform thedescribed functionality. The benefits provided by such functionality arenot limited to processing circuitry 870 alone or to other components ofnetwork node 860, but are enjoyed by network node 860 as a whole, and/orby end users and the wireless network generally.

Device readable medium 880 may comprise any form of volatile ornon-volatile computer readable memory including, without limitation,persistent storage, solid-state memory, remotely mounted memory,magnetic media, optical media, random access memory (RAM), read-onlymemory (ROM), mass storage media (for example, a hard disk), removablestorage media (for example, a flash drive, a Compact Disk (CD) or aDigital Video Disk (DVD)), and/or any other volatile or non-volatile,non-transitory device readable and/or computer-executable memory devicesthat store information, data, and/or instructions that may be used byprocessing circuitry 870. Device readable medium 880 may store anysuitable instructions, data or information, including a computerprogram, software, an application including one or more of logic, rules,code, tables, etc. and/or other instructions capable of being executedby processing circuitry 870 and, utilized by network node 860. Devicereadable medium 880 may be used to store any calculations made byprocessing circuitry 870 and/or any data received via interface 890. Insome embodiments, processing circuitry 870 and device readable medium880 may be considered to be integrated.

Interface 890 is used in the wired or wireless communication ofsignalling and/or data between network node 860, network 806, and/or WDs810. As illustrated, interface 890 comprises port(s)/terminal(s) 894 tosend and receive data, for example to and from network 806 over a wiredconnection. Interface 890 also includes radio front end circuitry 892that may be coupled to, or in certain embodiments a part of, antenna862. Radio front end circuitry 892 comprises filters 898 and amplifiers896. Radio front end circuitry 892 may be connected to antenna 862 andprocessing circuitry 870. Radio front end circuitry may be configured tocondition signals communicated between antenna 862 and processingcircuitry 870. Radio front end circuitry 892 may receive digital datathat is to be sent out to other network nodes or WDs via a wirelessconnection. Radio front end circuitry 892 may convert the digital datainto a radio signal having the appropriate channel and bandwidthparameters using a combination of filters 898 and/or amplifiers 896. Theradio signal may then be transmitted via antenna 862. Similarly, whenreceiving data, antenna 862 may collect radio signals which are thenconverted into digital data by radio front end circuitry 892. Thedigital data may be passed to processing circuitry 870. In otherembodiments, the interface may comprise different components and/ordifferent combinations of components.

In certain alternative embodiments, network node 860 may not includeseparate radio front end circuitry 892, instead, processing circuitry870 may comprise radio front end circuitry and may be connected toantenna 862 without separate radio front end circuitry 892. Similarly,in some embodiments, all or some of RF transceiver circuitry 872 may beconsidered a part of interface 890. In still other embodiments,interface 890 may include one or more ports or terminals 894, radiofront end circuitry 892, and RF transceiver circuitry 872, as part of aradio unit (not shown), and interface 890 may communicate with basebandprocessing circuitry 874, which is part of a digital unit (not shown).

Antenna 862 may include one or more antennas, or antenna arrays,configured to send and/or receive wireless signals. Antenna 862 may becoupled to radio front end circuitry 892 and may be any type of antennacapable of transmitting and receiving data and/or signals wirelessly. Insome embodiments, antenna 862 may comprise one or more omni-directional,sector or panel antennas operable to transmit/receive radio signalsbetween, for example, 2 GHz and 66 GHz. An omni-directional antenna maybe used to transmit/receive radio signals in any direction, a sectorantenna may be used to transmit/receive radio signals from deviceswithin a particular area, and a panel antenna may be a line of sightantenna used to transmit/receive radio signals in a relatively straightline. In some instances, the use of more than one antenna may bereferred to as MIMO. In certain embodiments, antenna 862 may be separatefrom network node 860 and may be connectable to network node 860 throughan interface or port.

Antenna 862, interface 890, and/or processing circuitry 870 may beconfigured to perform any receiving operations and/or certain obtainingoperations described herein as being performed by a network node. Anyinformation, data and/or signals may be received from a wireless device,another network node and/or any other network equipment. Similarly,antenna 862, interface 890, and/or processing circuitry 870 may beconfigured to perform any transmitting operations described herein asbeing performed by a network node. Any information, data and/or signalsmay be transmitted to a wireless device, another network node and/or anyother network equipment.

Power circuitry 887 may comprise, or be coupled to, power managementcircuitry and is configured to supply the components of network node 860with power for performing the functionality described herein. Powercircuitry 887 may receive power from power source 886. Power source 886and/or power circuitry 887 may be configured to provide power to thevarious components of network node 860 in a form suitable for therespective components (e.g., at a voltage and current level needed foreach respective component). Power source 886 may either be included in,or external to, power circuitry 887 and/or network node 860. Forexample, network node 860 may be connectable to an external power source(e.g., an electricity outlet) via an input circuitry or interface suchas an electrical cable, whereby the external power source supplies powerto power circuitry 887. As a further example, power source 886 maycomprise a source of power in the form of a battery or battery packwhich is connected to, or integrated in, power circuitry 887. Thebattery may provide backup power should the external power source fail.Other types of power sources, such as photovoltaic devices, may also beused.

Alternative embodiments of network node 860 may include additionalcomponents beyond those shown in FIG. 8 that may be responsible forproviding certain aspects of the network node's functionality, includingany of the functionality described herein and/or any functionalitynecessary to support the subject matter described herein. For example,network node 860 may include user interface equipment to allow input ofinformation into network node 860 and to allow output of informationfrom network node 860. This may allow a user to perform diagnostic,maintenance, repair, and other administrative functions for network node860.

As used herein, wireless device (WD) refers to a device capable,configured, arranged and/or operable to communicate wirelessly withnetwork nodes and/or other wireless devices. Unless otherwise noted, theterm WD may be used interchangeably herein with user equipment (UE).Communicating wirelessly may involve transmitting and/or receivingwireless signals using electromagnetic waves, radio waves, infraredwaves, and/or other types of signals suitable for conveying informationthrough air. In some embodiments, a WD may be configured to transmitand/or receive information without direct human interaction. Forinstance, a WD may be designed to transmit information to a network on apredetermined schedule, when triggered by an internal or external event,or in response to requests from the network. Examples of a WD include,but are not limited to, a smart phone, a mobile phone, a cell phone, avoice over IP (VoIP) phone, a wireless local loop phone, a desktopcomputer, a personal digital assistant (PDA), a wireless cameras, agaming console or device, a music storage device, a playback appliance,a wearable terminal device, a wireless endpoint, a mobile station, atablet, a laptop, a laptop-embedded equipment (LEE), a laptop-mountedequipment (LME), a smart device, a wireless customer-premise equipment(CPE). a vehicle-mounted wireless terminal device, etc. A WD may supportdevice-to-device (D2D) communication, for example by implementing a 3GPPstandard for sidelink communication, and may in this case be referred toas a D2D communication device. As yet another specific example, in anInternet of Things (IoT) scenario, a WD may represent a machine or otherdevice that performs monitoring and/or measurements, and transmits theresults of such monitoring and/or measurements to another WD and/or anetwork node. The WD may in this case be a machine-to-machine (M2M)device, which may in a 3GPP context be referred to as a machine-typecommunication (MTC) device. As one particular example, the WD may be aUE implementing the 3GPP narrow band internet of things (NB-IoT)standard. Particular examples of such machines or devices are sensors,metering devices such as power meters, industrial machinery, or home orpersonal appliances (e.g. refrigerators, televisions, etc.) personalwearables (e.g., watches, fitness trackers, etc.). In other scenarios, aWD may represent a vehicle or other equipment that is capable ofmonitoring and/or reporting on its operational status or other functionsassociated with its operation. A WD as described above may represent theendpoint of a wireless connection, in which case the device may bereferred to as a wireless terminal. Furthermore, a WD as described abovemay be mobile, in which case it may also be referred to as a mobiledevice or a mobile terminal.

As illustrated, wireless device 810 includes antenna 811, interface 814,processing circuitry 820, device readable medium 830, user interfaceequipment 832, auxiliary equipment 834, power source 836 and powercircuitry 837. WD 810 may include multiple sets of one or more of theillustrated components for different wireless technologies supported byWD 810, such as, for example, GSM, WCDMA, LTE, NR, WiFi, WiMAX, orBluetooth wireless technologies, just to mention a few. These wirelesstechnologies may be integrated into the same or different chips or setof chips as other components within WD 810.

Antenna 811 may include one or more antennas or antenna arraysconfigured to send and/or receive wireless signals, where the antenna811 is connected to interface 814. In certain alternative embodiments,antenna 811 may be separate from WD 810 and be connectable to WD 810through an interface or port. Antenna 811, interface 814, and/orprocessing circuitry 820 may be configured to perform any receiving ortransmitting operations described herein as being performed by a WD. Anyinformation, data and/or signals may be received from a network nodeand/or another WD. In some embodiments, radio front end circuitry and/orantenna 811 may be considered an interface.

As illustrated, interface 814 comprises radio front end circuitry 812and antenna 811. Radio front end circuitry 812 comprise one or morefilters 818 and amplifiers 816. Radio front end circuitry 812 isconnected to antenna 811 and processing circuitry 820, and is configuredto condition signals communicated between antenna 811 and processingcircuitry 820. Radio front end circuitry 812 may be coupled to or a partof antenna 811. In some embodiments, WD 810 may not include separateradio front end circuitry 812; rather, processing circuitry 820 maycomprise radio front end circuitry and may be connected to antenna 811.Similarly, in some embodiments, some or all of RF transceiver circuitry822 may be considered a part of interface 814. Radio front end circuitry812 may receive digital data that is to be sent out to other networknodes or WDs via a wireless connection. Radio front end circuitry 812may convert the digital data into a radio signal having the appropriatechannel and bandwidth parameters using a combination of filters 818and/or amplifiers 816. The radio signal may then be transmitted viaantenna 811. Similarly, when receiving data, antenna 811 may collectradio signals which are then converted into digital data by radio frontend circuitry 812. The digital data may be passed to processingcircuitry 820. In other embodiments, the interface may comprisedifferent components and/or different combinations of components.

Processing circuitry 820 may comprise a combination of one or more of amicroprocessor, controller, microcontroller, central processing unit,digital signal processor, application-specific integrated circuit, fieldprogrammable gate array, or any other suitable computing device,resource, or combination of hardware, software, and/or encoded logicoperable to provide, either alone or in conjunction with other WD 810components, such as device readable medium 830, WD 810 functionality.Such functionality may include providing any of the various wirelessfeatures or benefits discussed herein. For example, processing circuitry820 may execute instructions stored in device readable medium 830 or inmemory within processing circuitry 820 to provide the functionalitydisclosed herein.

As illustrated, processing circuitry 820 includes one or more of RFtransceiver circuitry 822, baseband processing circuitry 824, andapplication processing circuitry 826. In other embodiments, theprocessing circuitry may comprise different components and/or differentcombinations of components. In certain embodiments processing circuitry820 of WD 810 may comprise a SOC. In some embodiments, RF transceivercircuitry 822, baseband processing circuitry 824, and applicationprocessing circuitry 826 may be on separate chips or sets of chips. Inalternative embodiments, part or all of baseband processing circuitry824 and application processing circuitry 826 may be combined into onechip or set of chips, and RF transceiver circuitry 822 may be on aseparate chip or set of chips. In still alternative embodiments, part orall of RF transceiver circuitry 822 and baseband processing circuitry824 may be on the same chip or set of chips, and application processingcircuitry 826 may be on a separate chip or set of chips. In yet otheralternative embodiments, part or all of RF transceiver circuitry 822,baseband processing circuitry 824, and application processing circuitry826 may be combined in the same chip or set of chips. In someembodiments, RF transceiver circuitry 822 may be a part of interface814. RF transceiver circuitry 822 may condition RF signals forprocessing circuitry 820.

In certain embodiments, some or all of the functionality describedherein as being performed by a WD may be provided by processingcircuitry 820 executing instructions stored on device readable medium830, which in certain embodiments may be a computer-readable storagemedium. In alternative embodiments, some or all of the functionality maybe provided by processing circuitry 820 without executing instructionsstored on a separate or discrete device readable storage medium, such asin a hard-wired manner. In any of those particular embodiments, whetherexecuting instructions stored on a device readable storage medium ornot, processing circuitry 820 can be configured to perform the describedfunctionality. The benefits provided by such functionality are notlimited to processing circuitry 820 alone or to other components of WD810, but are enjoyed by WD 810 as a whole, and/or by end users and thewireless network generally.

Processing circuitry 820 may be configured to perform any determining,calculating, or similar operations (e.g., certain obtaining operations)described herein as being performed by a WD. These operations, asperformed by processing circuitry 820, may include processinginformation obtained by processing circuitry 820 by, for example,converting the obtained information into other information, comparingthe obtained information or converted information to information storedby WD 810, and/or performing one or more operations based on theobtained information or converted information, and as a result of saidprocessing making a determination.

Device readable medium 830 may be operable to store a computer program,software, an application including one or more of logic, rules, code,tables, etc. and/or other instructions capable of being executed byprocessing circuitry 820. Device readable medium 830 may includecomputer memory (e.g., Random Access Memory (RAM) or Read Only Memory(ROM)), mass storage media (e.g., a hard disk), removable storage media(e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or anyother volatile or non-volatile, non-transitory device readable and/orcomputer executable memory devices that store information, data, and/orinstructions that may be used by processing circuitry 820. In someembodiments, processing circuitry 820 and device readable medium 830 maybe considered to be integrated.

User interface equipment 832 may provide components that allow for ahuman user to interact with WD 810. Such interaction may be of manyforms, such as visual, audial, tactile, etc. User interface equipment832 may be operable to produce output to the user and to allow the userto provide input to WD 810. The type of interaction may vary dependingon the type of user interface equipment 832 installed in WD 810. Forexample, if WD 810 is a smart phone, the interaction may be via a touchscreen; if WD 810 is a smart meter, the interaction may be through ascreen that provides usage (e.g., the number of gallons used) or aspeaker that provides an audible alert (e.g., if smoke is detected).User interface equipment 832 may include input interfaces, devices andcircuits, and output interfaces, devices and circuits. User interfaceequipment 832 is configured to allow input of information into WD 810,and is connected to processing circuitry 820 to allow processingcircuitry 820 to process the input information. User interface equipment832 may include, for example, a microphone, a proximity or other sensor,keys/buttons, a touch display, one or more cameras, a USB port, or otherinput circuitry. User interface equipment 832 is also configured toallow output of information from WD 810, and to allow processingcircuitry 820 to output information from WD 810. User interfaceequipment 832 may include, for example, a speaker, a display, vibratingcircuitry, a USB port, a headphone interface, or other output circuitry.Using one or more input and output interfaces, devices, and circuits, ofuser interface equipment 832, WD 810 may communicate with end usersand/or the wireless network, and allow them to benefit from thefunctionality described herein.

Auxiliary equipment 834 is operable to provide more specificfunctionality which may not be generally performed by WDs. This maycomprise specialized sensors for doing measurements for variouspurposes, interfaces for additional types of communication such as wiredcommunications etc. The inclusion and type of components of auxiliaryequipment 834 may vary depending on the embodiment and/or scenario.

Power source 836 may, in some embodiments, be in the form of a batteryor battery pack. Other types of power sources, such as an external powersource (e.g., an electricity outlet), photovoltaic devices or powercells, may also be used. WD 810 may further comprise power circuitry 837for delivering power from power source 836 to the various parts of WD810 which need power from power source 836 to carry out anyfunctionality described or indicated herein. Power circuitry 837 may incertain embodiments comprise power management circuitry. Power circuitry837 may additionally or alternatively be operable to receive power froman external power source; in which case WD 810 may be connectable to theexternal power source (such as an electricity outlet) via inputcircuitry or an interface such as an electrical power cable. Powercircuitry 837 may also in certain embodiments be operable to deliverpower from an external power source to power source 836. This may be,for example, for the charging of power source 836. Power circuitry 837may perform any formatting, converting, or other modification to thepower from power source 836 to make the power suitable for therespective components of WD 810 to which power is supplied.

FIG. 9 illustrates one embodiment of a UE in accordance with variousaspects described herein. As used herein, a user equipment or UE may notnecessarily have a user in the sense of a human user who owns and/oroperates the relevant device. Instead, a UE may represent a device thatis intended for sale to, or operation by, a human user but which maynot, or which may not initially, be associated with a specific humanuser. A UE may also comprise any UE identified by the 3rd GenerationPartnership Project (3GPP), including a NB-IoT UE that is not intendedfor sale to, or operation by, a human user. UE 900, as illustrated inFIG. 9, is one example of a WD configured for communication inaccordance with one or more communication standards promulgated by the3rd Generation Partnership Project (3GPP), such as 3GPP's GSM, UMTS,LTE, and/or 5G standards. As mentioned previously, the term WD and UEmay be used interchangeable. Accordingly, although FIG. 9 is a UE, thecomponents discussed herein are equally applicable to a WD, andvice-versa.

In FIG. 9, UE 900 includes processing circuitry 901 that is operativelycoupled to input/output interface 905, radio frequency (RF) interface909, network connection interface 911, memory 915 including randomaccess memory (RAM) 917, read-only memory (ROM) 919, and storage medium921 or the like, communication subsystem 931, power source 913, and/orany other component, or any combination thereof. Storage medium 921includes operating system 923, application program 925, and data 927. Inother embodiments, storage medium 921 may include other similar types ofinformation. Certain UEs may utilize all of the components shown in FIG.9, or only a subset of the components. The level of integration betweenthe components may vary from one UE to another UE. Further, certain UEsmay contain multiple instances of a component, such as multipleprocessors, memories, transceivers, transmitters, receivers, etc.

In FIG. 9, processing circuitry 901 may be configured to processcomputer instructions and data. Processing circuitry 901 may beconfigured to implement any sequential state machine operative toexecute machine instructions stored as machine-readable computerprograms in the memory, such as one or more hardware-implemented statemachines (e.g., in discrete logic, FPGA, ASIC, etc.); programmable logictogether with appropriate firmware; one or more stored program,general-purpose processors, such as a microprocessor or Digital SignalProcessor (DSP), together with appropriate software; or any combinationof the above. For example, the processing circuitry 901 may include twocentral processing units (CPUs). Data may be information in a formsuitable for use by a computer.

In the depicted embodiment, input/output interface 905 may be configuredto provide a communication interface to an input device, output device,or input and output device. UE 900 may be configured to use an outputdevice via input/output interface 905. An output device may use the sametype of interface port as an input device. For example, a USB port maybe used to provide input to and output from UE 900. The output devicemay be a speaker, a sound card, a video card, a display, a monitor, aprinter, an actuator, an emitter, a smartcard, another output device, orany combination thereof. UE 900 may be configured to use an input devicevia input/output interface 905 to allow a user to capture informationinto UE 900. The input device may include a touch-sensitive orpresence-sensitive display, a camera (e.g., a digital camera, a digitalvideo camera, a web camera, etc.), a microphone, a sensor, a mouse, atrackball, a directional pad, a trackpad, a scroll wheel, a smartcard,and the like. The presence-sensitive display may include a capacitive orresistive touch sensor to sense input from a user. A sensor may be, forinstance, an accelerometer, a gyroscope, a tilt sensor, a force sensor,a magnetometer, an optical sensor, a proximity sensor, another likesensor, or any combination thereof. For example, the input device may bean accelerometer, a magnetometer, a digital camera, a microphone, and anoptical sensor.

In FIG. 9, RF interface 909 may be configured to provide a communicationinterface to RF components such as a transmitter, a receiver, and anantenna. Network connection interface 911 may be configured to provide acommunication interface to network 943 a. Network 943 a may encompasswired and/or wireless networks such as a local-area network (LAN), awide-area network (WAN), a computer network, a wireless network, atelecommunications network, another like network or any combinationthereof. For example, network 943 a may comprise a Wi-Fi network.Network connection interface 911 may be configured to include a receiverand a transmitter interface used to communicate with one or more otherdevices over a communication network according to one or morecommunication protocols, such as Ethernet, TCP/IP, SONET, ATM, or thelike. Network connection interface 911 may implement receiver andtransmitter functionality appropriate to the communication network links(e.g., optical, electrical, and the like). The transmitter and receiverfunctions may share circuit components, software or firmware, oralternatively may be implemented separately.

RAM 917 may be configured to interface via bus 902 to processingcircuitry 901 to provide storage or caching of data or computerinstructions during the execution of software programs such as theoperating system, application programs, and device drivers. ROM 919 maybe configured to provide computer instructions or data to processingcircuitry 901. For example, ROM 919 may be configured to store invariantlow-level system code or data for basic system functions such as basicinput and output (I/O), startup, or reception of keystrokes from akeyboard that are stored in a non-volatile memory. Storage medium 921may be configured to include memory such as RAM, ROM, programmableread-only memory (PROM), erasable programmable read-only memory (EPROM),electrically erasable programmable read-only memory (EEPROM), magneticdisks, optical disks, floppy disks, hard disks, removable cartridges, orflash drives. In one example, storage medium 921 may be configured toinclude operating system 923, application program 925 such as a webbrowser application, a widget or gadget engine or another application,and data file 927. Storage medium 921 may store, for use by UE 900, anyof a variety of various operating systems or combinations of operatingsystems.

Storage medium 921 may be configured to include a number of physicaldrive units, such as redundant array of independent disks (RAID), floppydisk drive, flash memory, USB flash drive, external hard disk drive,thumb drive, pen drive, key drive, high-density digital versatile disc(HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray opticaldisc drive, holographic digital data storage (HDDS) optical disc drive,external mini-dual in-line memory module (DIMM), synchronous dynamicrandom access memory (SDRAM), external micro-DIMM SDRAM, smartcardmemory such as a subscriber identity module or a removable user identity(SIM/RUIM) module, other memory, or any combination thereof. Storagemedium 921 may allow UE 900 to access computer-executable instructions,application programs or the like, stored on transitory or non-transitorymemory media, to off-load data, or to upload data. An article ofmanufacture, such as one utilizing a communication system may betangibly embodied in storage medium 921, which may comprise a devicereadable medium.

In FIG. 9, processing circuitry 901 may be configured to communicatewith network 943 b using communication subsystem 931. Network 943 a andnetwork 943 b may be the same network or networks or different networkor networks. Communication subsystem 931 may be configured to includeone or more transceivers used to communicate with network 943 b. Forexample, communication subsystem 931 may be configured to include one ormore transceivers used to communicate with one or more remotetransceivers of another device capable of wireless communication such asanother WD, UE, or base station of a radio access network (RAN)according to one or more communication protocols, such as IEEE 802.9,CDMA, WCDMA, GSM, LTE, UTRAN, WiMax, or the like. Each transceiver mayinclude transmitter 933 and/or receiver 935 to implement transmitter orreceiver functionality, respectively, appropriate to the RAN links(e.g., frequency allocations and the like). Further, transmitter 933 andreceiver 935 of each transceiver may share circuit components, softwareor firmware, or alternatively may be implemented separately.

In the illustrated embodiment, the communication functions ofcommunication subsystem 931 may include data communication, voicecommunication, multimedia communication, short-range communications suchas Bluetooth, near-field communication, location-based communicationsuch as the use of the global positioning system (GPS) to determine alocation, another like communication function, or any combinationthereof. For example, communication subsystem 931 may include cellularcommunication, Wi-Fi communication, Bluetooth communication, and GPScommunication. Network 943 b may encompass wired and/or wirelessnetworks such as a local-area network (LAN), a wide-area network (WAN),a computer network, a wireless network, a telecommunications network,another like network or any combination thereof. For example, network943 b may be a cellular network, a Wi-Fi network, and/or a near-fieldnetwork. Power source 913 may be configured to provide alternatingcurrent (AC) or direct current (DC) power to components of UE 900.

The features, benefits and/or functions described herein may beimplemented in one of the components of UE 900 or partitioned acrossmultiple components of UE 900. Further, the features, benefits, and/orfunctions described herein may be implemented in any combination ofhardware, software or firmware. In one example, communication subsystem931 may be configured to include any of the components described herein.Further, processing circuitry 901 may be configured to communicate withany of such components over bus 902. In another example, any of suchcomponents may be represented by program instructions stored in memorythat when executed by processing circuitry 901 perform the correspondingfunctions described herein. In another example, the functionality of anyof such components may be partitioned between processing circuitry 901and communication subsystem 931. In another example, thenon-computationally intensive functions of any of such components may beimplemented in software or firmware and the computationally intensivefunctions may be implemented in hardware.

FIG. 10 is a schematic block diagram illustrating a virtualizationenvironment 1000 in which functions implemented by some embodiments maybe virtualized. In the present context, virtualizing means creatingvirtual versions of apparatuses or devices which may includevirtualizing hardware platforms, storage devices and networkingresources. As used herein, virtualization can be applied to a node(e.g., a virtualized base station or a virtualized radio access node) orto a device (e.g., a UE, a wireless device or any other type ofcommunication device) or components thereof and relates to animplementation in which at least a portion of the functionality isimplemented as one or more virtual components (e.g., via one or moreapplications, components, functions, virtual machines or containersexecuting on one or more physical processing nodes in one or morenetworks).

In some embodiments, some or all of the functions described herein maybe implemented as virtual components executed by one or more virtualmachines implemented in one or more virtual environments 1000 hosted byone or more of hardware nodes 1030. Further, in embodiments in which thevirtual node is not a radio access node or does not require radioconnectivity (e.g., a core network node), then the network node may beentirely virtualized.

The functions may be implemented by one or more applications 1020 (whichmay alternatively be called software instances, virtual appliances,network functions, virtual nodes, virtual network functions, etc.)operative to implement some of the features, functions, and/or benefitsof some of the embodiments disclosed herein. Applications 1020 are runin virtualization environment 1000 which provides hardware 1030comprising processing circuitry 1060 and memory 1090. Memory 1090contains instructions 1095 executable by processing circuitry 1060whereby application 1020 is operative to provide one or more of thefeatures, benefits, and/or functions disclosed herein.

Virtualization environment 1000, comprises general-purpose orspecial-purpose network hardware devices 1030 comprising a set of one ormore processors or processing circuitry 1060, which may be commercialoff-the-shelf (COTS) processors, dedicated Application SpecificIntegrated Circuits (ASICs), or any other type of processing circuitryincluding digital or analog hardware components or special purposeprocessors. Each hardware device may comprise memory 1090-1 which may benon-persistent memory for temporarily storing instructions 1095 orsoftware executed by processing circuitry 1060. Each hardware device maycomprise one or more network interface controllers (NICs) 1070, alsoknown as network interface cards, which include physical networkinterface 1080. Each hardware device may also include non-transitory,persistent, machine-readable storage media 1090-2 having stored thereinsoftware 1095 and/or instructions executable by processing circuitry1060. Software 1095 may include any type of software including softwarefor instantiating one or more virtualization layers 1050 (also referredto as hypervisors), software to execute virtual machines 1040 as well assoftware allowing it to execute functions, features and/or benefitsdescribed in relation with some embodiments described herein.

Virtual machines 1040, comprise virtual processing, virtual memory,virtual networking or interface and virtual storage, and may be run by acorresponding virtualization layer 1050 or hypervisor. Differentembodiments of the instance of virtual appliance 1020 may be implementedon one or more of virtual machines 1040, and the implementations may bemade in different ways.

During operation, processing circuitry 1060 executes software 1095 toinstantiate the hypervisor or virtualization layer 1050, which maysometimes be referred to as a virtual machine monitor (VMM).Virtualization layer 1050 may present a virtual operating platform thatappears like networking hardware to virtual machine 1040.

As shown in FIG. 10, hardware 1030 may be a standalone network node withgeneric or specific components. Hardware 1030 may comprise antenna 10225and may implement some functions via virtualization. Alternatively,hardware 1030 may be part of a larger cluster of hardware (e.g. such asin a data center or customer premise equipment (CPE)) where manyhardware nodes work together and are managed via management andorchestration (MANO) 10100, which, among others, oversees lifecyclemanagement of applications 1020.

Virtualization of the hardware is in some contexts referred to asnetwork function virtualization (NFV). NFV may be used to consolidatemany network equipment types onto industry standard high volume serverhardware, physical switches, and physical storage, which can be locatedin data centers, and customer premise equipment.

In the context of NFV, virtual machine 1040 may be a softwareimplementation of a physical machine that runs programs as if they wereexecuting on a physical, non-virtualized machine. Each of virtualmachines 1040, and that part of hardware 1030 that executes that virtualmachine, be it hardware dedicated to that virtual machine and/orhardware shared by that virtual machine with others of the virtualmachines 1040, forms a separate virtual network elements (VNE).

Still in the context of NFV, Virtual Network Function (VNF) isresponsible for handling specific network functions that run in one ormore virtual machines 1040 on top of hardware networking infrastructure1030 and corresponds to application 1020 in FIG. 10.

In some embodiments, one or more radio units 10200 that each include oneor more transmitters 10220 and one or more receivers 10210 may becoupled to one or more antennas 10225. Radio units 10200 may communicatedirectly with hardware nodes 1030 via one or more appropriate networkinterfaces and may be used in combination with the virtual components toprovide a virtual node with radio capabilities, such as a radio accessnode or a base station.

In some embodiments, some signalling can be effected with the use ofcontrol system 10230 which may alternatively be used for communicationbetween the hardware nodes 1030 and radio units 10200.

With reference to FIG. 11, in accordance with an embodiment, acommunication system includes telecommunication network 1110, such as a3GPP-type cellular network, which comprises access network 1111, such asa radio access network, and core network 1114. Access network 1111comprises a plurality of base stations 1112 a, 1112 b, 1112 c, such asNBs, eNBs, gNBs or other types of wireless access points, each defininga corresponding coverage area 1113 a, 1113 b, 1113 c. Each base station1112 a, 1112 b, 1112 c is connectable to core network 1114 over a wiredor wireless connection 1115. A first UE 1191 located in coverage area1113 c is configured to wirelessly connect to, or be paged by, thecorresponding base station 1112 c. A second UE 1192 in coverage area1113 a is wirelessly connectable to the corresponding base station 1112a. While a plurality of UEs 1191, 1192 are illustrated in this example,the disclosed embodiments are equally applicable to a situation where asole UE is in the coverage area or where a sole UE is connecting to thecorresponding base station 1112.

Telecommunication network 1110 is itself connected to host computer1130, which may be embodied in the hardware and/or software of astandalone server, a cloud-implemented server, a distributed server oras processing resources in a server farm. Host computer 1130 may beunder the ownership or control of a service provider, or may be operatedby the service provider or on behalf of the service provider.Connections 1121 and 1122 between telecommunication network 1110 andhost computer 1130 may extend directly from core network 1114 to hostcomputer 1130 or may go via an optional intermediate network 1120.Intermediate network 1120 may be one of, or a combination of more thanone of, a public, private or hosted network; intermediate network 1120,if any, may be a backbone network or the Internet; in particular,intermediate network 1120 may comprise two or more sub-networks (notshown).

The communication system of FIG. 11 as a whole enables connectivitybetween the connected UEs 1191, 1192 and host computer 1130. Theconnectivity may be described as an over-the-top (OTT) connection 1150.Host computer 1130 and the connected UEs 1191, 1192 are configured tocommunicate data and/or signaling via OTT connection 1150, using accessnetwork 1111, core network 1114, any intermediate network 1120 andpossible further infrastructure (not shown) as intermediaries. OTTconnection 1150 may be transparent in the sense that the participatingcommunication devices through which OTT connection 1150 passes areunaware of routing of uplink and downlink communications. For example,base station 1112 may not or need not be informed about the past routingof an incoming downlink communication with data originating from hostcomputer 1130 to be forwarded (e.g., handed over) to a connected UE1191. Similarly, base station 1112 need not be aware of the futurerouting of an outgoing uplink communication originating from the UE 1191towards the host computer 1130.

Example implementations, in accordance with an embodiment, of the UE,base station and host computer discussed in the preceding paragraphswill now be described with reference to FIG. 12. In communication system1200, host computer 1210 comprises hardware 1215 including communicationinterface 1216 configured to set up and maintain a wired or wirelessconnection with an interface of a different communication device ofcommunication system 1200. Host computer 1210 further comprisesprocessing circuitry 1218, which may have storage and/or processingcapabilities. In particular, processing circuitry 1218 may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. Host computer 1210 furthercomprises software 1211, which is stored in or accessible by hostcomputer 1210 and executable by processing circuitry 1218. Software 1211includes host application 1212. Host application 1212 may be operable toprovide a service to a remote user, such as UE 1230 connecting via OTTconnection 1250 terminating at UE 1230 and host computer 1210. Inproviding the service to the remote user, host application 1212 mayprovide user data which is transmitted using OTT connection 1250.

Communication system 1200 further includes base station 1220 provided ina telecommunication system and comprising hardware 1225 enabling it tocommunicate with host computer 1210 and with UE 1230. Hardware 1225 mayinclude communication interface 1226 for setting up and maintaining awired or wireless connection with an interface of a differentcommunication device of communication system 1200, as well as radiointerface 1227 for setting up and maintaining at least wirelessconnection 1270 with UE 1230 located in a coverage area (not shown inFIG. 12) served by base station 1220. Communication interface 1226 maybe configured to facilitate connection 1260 to host computer 1210.Connection 1260 may be direct or it may pass through a core network (notshown in FIG. 12) of the telecommunication system and/or through one ormore intermediate networks outside the telecommunication system. In theembodiment shown, hardware 1225 of base station 1220 further includesprocessing circuitry 1228, which may comprise one or more programmableprocessors, application-specific integrated circuits, field programmablegate arrays or combinations of these (not shown) adapted to executeinstructions. Base station 1220 further has software 1221 storedinternally or accessible via an external connection.

Communication system 1200 further includes UE 1230 already referred to.Its hardware 1235 may include radio interface 1237 configured to set upand maintain wireless connection 1270 with a base station serving acoverage area in which UE 1230 is currently located. Hardware 1235 of UE1230 further includes processing circuitry 1238, which may comprise oneor more programmable processors, application-specific integratedcircuits, field programmable gate arrays or combinations of these (notshown) adapted to execute instructions. UE 1230 further comprisessoftware 1231, which is stored in or accessible by UE 1230 andexecutable by processing circuitry 1238. Software 1231 includes clientapplication 1232. Client application 1232 may be operable to provide aservice to a human or non-human user via UE 1230, with the support ofhost computer 1210. In host computer 1210, an executing host application1212 may communicate with the executing client application 1232 via OTTconnection 1250 terminating at UE 1230 and host computer 1210. Inproviding the service to the user, client application 1232 may receiverequest data from host application 1212 and provide user data inresponse to the request data. OTT connection 1250 may transfer both therequest data and the user data. Client application 1232 may interactwith the user to generate the user data that it provides.

It is noted that host computer 1210, base station 1220 and UE 1230illustrated in FIG. 12 may be similar or identical to host computer1130, one of base stations 1112 a, 1112 b, 1112 c and one of UEs 1191,1192 of FIG. 11, respectively. This is to say, the inner workings ofthese entities may be as shown in FIG. 12 and independently, thesurrounding network topology may be that of FIG. 11.

In FIG. 12, OTT connection 1250 has been drawn abstractly to illustratethe communication between host computer 1210 and UE 1230 via basestation 1220, without explicit reference to any intermediary devices andthe precise routing of messages via these devices. Networkinfrastructure may determine the routing, which it may be configured tohide from UE 1230 or from the service provider operating host computer1210, or both. While OTT connection 1250 is active, the networkinfrastructure may further take decisions by which it dynamicallychanges the routing (e.g., on the basis of load balancing considerationor reconfiguration of the network).

Wireless connection 1270 between UE 1230 and base station 1220 is inaccordance with the teachings of the embodiments described throughoutthis disclosure. One or more of the various embodiments improve theperformance of OTT services provided to UE 1230 using OTT connection1250, in which wireless connection 1270 forms the last segment. Moreprecisely, the teachings of these embodiments may improve the data rate,latency, and power consumption, and thereby provide benefits such asreduced user waiting time, better responsiveness, and extended batterytime, among others.

A measurement procedure may be provided for the purpose of monitoringdata rate, latency and other factors on which the one or moreembodiments improve. There may further be an optional networkfunctionality for reconfiguring OTT connection 1250 between hostcomputer 1210 and UE 1230, in response to variations in the measurementresults. The measurement procedure and/or the network functionality forreconfiguring OTT connection 1250 may be implemented in software 1211and hardware 1215 of host computer 1210 or in software 1231 and hardware1235 of UE 1230, or both. In embodiments, sensors (not shown) may bedeployed in or in association with communication devices through whichOTT connection 1250 passes; the sensors may participate in themeasurement procedure by supplying values of the monitored quantitiesexemplified above, or supplying values of other physical quantities fromwhich software 1211, 1231 may compute or estimate the monitoredquantities. The reconfiguring of OTT connection 1250 may include messageformat, retransmission settings, preferred routing etc.; thereconfiguring need not affect base station 1220, and it may be unknownor imperceptible to base station 1220. Such procedures andfunctionalities may be known and practiced in the art. In certainembodiments, measurements may involve proprietary UE signalingfacilitating host computer 1210's measurements of throughput,propagation times, latency and the like. The measurements may beimplemented in that software 1211 and 1231 causes messages to betransmitted, in particular empty or ‘dummy’ messages, using OTTconnection 1250 while it monitors propagation times, errors etc.

FIG. 13 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 11 and 12. Forsimplicity of the present disclosure, only drawing references to FIG. 13will be included in this section. In step 1310, the host computerprovides user data. In substep 1311 (which may be optional) of step1310, the host computer provides the user data by executing a hostapplication. In step 1320, the host computer initiates a transmissioncarrying the user data to the UE. In step 1330 (which may be optional),the base station transmits to the UE the user data which was carried inthe transmission that the host computer initiated, in accordance withthe teachings of the embodiments described throughout this disclosure.In step 1340 (which may also be optional), the UE executes a clientapplication associated with the host application executed by the hostcomputer.

FIG. 14 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 11 and 12. Forsimplicity of the present disclosure, only drawing references to FIG. 14will be included in this section. In step 1410 of the method, the hostcomputer provides user data. In an optional substep (not shown) the hostcomputer provides the user data by executing a host application. In step1420, the host computer initiates a transmission carrying the user datato the UE. The transmission may pass via the base station, in accordancewith the teachings of the embodiments described throughout thisdisclosure. In step 1430 (which may be optional), the UE receives theuser data carried in the transmission.

FIG. 15 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 11 and 12. Forsimplicity of the present disclosure, only drawing references to FIG. 15will be included in this section. In step 1510 (which may be optional),the UE receives input data provided by the host computer. Additionallyor alternatively, in step 1520, the UE provides user data. In substep1521 (which may be optional) of step 1520, the UE provides the user databy executing a client application. In substep 1511 (which may beoptional) of step 1510, the UE executes a client application whichprovides the user data in reaction to the received input data providedby the host computer. In providing the user data, the executed clientapplication may further consider user input received from the user.Regardless of the specific manner in which the user data was provided,the UE initiates, in substep 1530 (which may be optional), transmissionof the user data to the host computer. In step 1540 of the method, thehost computer receives the user data transmitted from the UE, inaccordance with the teachings of the embodiments described throughoutthis disclosure.

FIG. 16 is a flowchart illustrating a method implemented in acommunication system, in accordance with one embodiment. Thecommunication system includes a host computer, a base station and a UEwhich may be those described with reference to FIGS. 11 and 12. Forsimplicity of the present disclosure, only drawing references to FIG. 16will be included in this section. In step 1610 (which may be optional),in accordance with the teachings of the embodiments described throughoutthis disclosure, the base station receives user data from the UE. Instep 1620 (which may be optional), the base station initiatestransmission of the received user data to the host computer. In step1630 (which may be optional), the host computer receives the user datacarried in the transmission initiated by the base station.

Any appropriate steps, methods, features, functions, or benefitsdisclosed herein may be performed through one or more functional units,circuits, or modules of one or more virtual apparatuses. Each virtualapparatus may comprise a number of these functional units. Thesefunctional units may be implemented via processing circuitry, which mayinclude one or more microprocessor or microcontrollers, as well as otherdigital hardware, which may include digital signal processors (DSPs),special-purpose digital logic, and the like. The processing circuitrymay be configured to execute program code stored in memory, which mayinclude one or several types of memory such as read-only memory (ROM),random-access memory (RAM), cache memory, flash memory devices, opticalstorage devices, etc. Program code stored in memory includes programinstructions for executing one or more telecommunications and/or datacommunications protocols as well as instructions for carrying out one ormore of the techniques described herein. In some implementations, theprocessing circuitry may be used to cause the respective functional unitto perform corresponding functions according one or more embodiments ofthe present disclosure.

The solution presented herein may, of course, be carried out in otherways than those specifically set forth herein without departing fromessential characteristics of the solution presented herein. The presentembodiments are to be considered in all respects as illustrative and notrestrictive, and all changes coming within the meaning and equivalencyrange of the appended claims are intended to be embraced therein.

The following, which was included with the corresponding ProvisionalApplication, is the standards submissions associated with the solutionpresented herein.

3GPP TSG-RAN WG3 #97bis R3-173956

Prague, Czech Republic, 9-13 Oct. 2017

Agenda Item: 10.8.3.1

Source: Ericsson

Title: Enhancement on the Downlink Data Delivery Status

Document for: pCR

Introduction

In the past meetings, different flow control enhancements have beensubmitted to RAN3.

We discuss in this paper the enhancement we may consider in DownlinkData Delivery Status.

Discussion

In the Downlink Data Delivery Status (DDDS) message, there below threeinformation elements are mandatory presented:

-   -   the highest PDCP PDU sequence number successfully delivered in        sequence to the UE among those PDCP PDUs received from the gNB        hosting the PDCP entity;    -   the desired buffer size in bytes for the concerned data bearer;    -   the minimum desired buffer size in bytes for the UE;

This implies that firstly the DDDS is meant for the RLC AM mode andsecondly the Downlink Data Delivery Status sending frequency isdetermined by the RLC Acked rate.

We see the need to send the first DDDS early than the first RLC Acked toindicate to the node hosting the PDCP entity the desired buffer size,and also the case to using DDDS to only provide the information on thedesired buffer size and the minimum desired buffer size with the absenceof the highest PDCP PDU sequence number successfully delivered. Thus weneed to introduce a way in DDDS to make the highest PDCP PDU sequencenumber successfully delivered an optional information element.

Proposal 1: RAN3 to Agree to Make the Highest PDCP PDU Sequence NumberSuccessfully Delivered Optional.

DDDS could be useful both for RLC AM and RLC UM. For UM flow control, itis sufficient to get updates on what had been transmitted to the lowerlayer (e.g. MAC layer).

Highest transmitted PDCP Sequence Number is meant to be the highest PDCPSN that has been requested by MAC for transmission over the Uuinterface. To introduce this in to DDDS, we may get more frequent DDDSreport than the RLC Acked rate, so the node hosting PDCP entity couldhave more up to date status information. Further it also providesinformation for the node hosting PDCP entity the transmission status ofthe PDCP PDUs to the lower layer, however it can not be used to removethe PDCP PDU in RLC AM mode.

Proposal 2: RAN3 to Agree to Include the Highest Transmitted PDCPSequence Number in DDDS.

To use the DDDS for RLC UM mode, we need to modify the definition forthe two mandatory IEs, desired buffer size and minimum desired buffersize, so when apply to RLC UM mode, they refer to the user datatransmitted to MAC layer.

Proposal 3: RAN3 to Agree to Modify Desired Buffer Size and MinimumDesired Buffer Size to Cover RLC UM Mode.

The highest transmitted PDCP Sequence Number to MAC layer is meant to beused both for RLC UM and RLC AM. To ensure that we could use DDDSwithout always needing to include the highest transmitted PDCP SequenceNumber, in the case that we wish to send DDDS before any datatransmission, and in the case that we only wish to update the desiredbuffer size and in the case that there is no change to the highesttransmitted PDCP Sequence Number so we do not need to repeat the sameinformation, we propose to also make this information element optional.

Proposal 4: RAN3 to Agree to Make the Highest Transmitted PDCP SequenceNumber Optional.

There are only 2 spare bits left in the DDDS frame format. In ouropinion, it is beneficial to add more spare bits. Thus we may considerto include 1 octet spare bits for future extension.

Proposal 5: RAN3 to Consider to Add One Octet Spare Bits in DDDS Frame.

Conclusions and Proposals

Proposal 1: RAN3 to agree to make the highest PDCP PDU sequence numbersuccessfully delivered optional.

Proposal 2: RAN3 to agree to include the highest transmitted PDCPSequence Number in DDDS.

Proposal 3: RAN3 to agree to modify desired buffer size and minimumdesired buffer size to cover RLC UM mode.

Proposal 4: RAN3 to agree to make the highest transmitted PDCP SequenceNumber optional.

Proposal 5: RAN3 to consider to add one octet spare bits in DDDS frame.

Text Proposal to TS 38.425 v 0.1.0

5.2 Xn user plane protocol layer services

Editor's Note: All the text below is For Further Study (FFS).

The following functions are provided by the Xn UP protocol for dualconnectivity:

-   -   Provision of Xn UP specific sequence number information for user        data transferred from the MgNB to the SgNB for a specific data        bearer configured with the split bearer option;    -   Information of successful in sequence delivery of PDCP PDUs to        the UE from SgNB for user data associated with a specific data        bearer configured with the split bearer option;    -   Information of successful in sequence transmitted PDCP PDUs to        the MAC layer from S-NG-RAN node for user data associated with a        specific data bearer configured with the split bearer option;    -   Information of PDCP PDUs that were not delivered to the UE;    -   Information of the currently desired buffer size at the SgNB for        transmitting to the UE user data or MAC layer associated with a        specific data bearer configured with the split bearer option;    -   Information of the currently minimum desired buffer size at the        SgNB for transmitting to the UE user data or MAC layer        associated with all data bearers configured with the split        bearer option.

The following functions are provided by the Xn UP protocol for the SCGsplit bearer for dual connectivity with NR in E-UTRAN:

-   -   Provision of Xn UP specific sequence number information for user        data transferred from the SgNB to the MgNB for a specific data        bearer configured with the SCG split bearer option;    -   Information of successful in sequence delivery of PDCP PDUs to        the UE from MgNB for user data associated with a specific data        bearer configured with the SCG split bearer option;    -   Information of successful in sequence transmitted PDCP PDUs to        the MAC layer from M-NG-RAN node for user data associated with a        specific data bearer configured with the SCG split bearer        option;    -   Information of PDCP PDUs from the MgNB that were not delivered        to the UE;    -   Information of the currently desired buffer size at the MgNB for        transmitting to the UE user data or MAC layer associated with a        specific data bearer configured with the split bearer option;    -   Information of the currently minimum desired buffer size at the        MgNB for transmitting to the UE user data or MAC layer        associated with all data bearers configured with the split        bearer option.

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5.4.2 Downlink Data Delivery Status

Editor's Note: All the text below is FFS [for further study].

The purpose of the Downlink Data Delivery Status procedure is to providefeedback from the corresponding gNB to the gNB hosting the PDCP entityto allow the gNB hosting the PDCP entity to control the downlink userdata flow via the corresponding gNB for the respective data bearer. Thecorresponding gNB may also transfer uplink user data for the concerneddata bearer to the gNB hosting the PDCP entity together with a DL DATADELIVERY STATUS frame within the same GTP-U PDU.

The Downlink Data Delivery Status procedure is also used to providefeedback from the corresponding gNB to the gNB hosting the PDCP entityto allow the gNB hosting the PDCP entity to control the successfuldelivery of DL control data to the corresponding gNB. In this case thecorresponding gNB is always the SgNB and the gNB hosting the PDCP entityis always the MgNB [FFS whether this sentence needs rewording].

When the corresponding gNB decides to trigger the Feedback for DownlinkData Delivery procedure it shall report:

a) the highest PDCP PDU sequence number successfully delivered insequence to the UE among those PDCP PDUs received from the gNB hostingthe PDCP entity; it is used for RLC AM only.

b) the desired buffer size in bytes for the concerned data bearer;

c) the minimum desired buffer size in bytes for the UE or MAC layer;

d) the Xn-U packets that were declared as being “lost” by thecorresponding gNB and have not yet been reported to the gNB hosting thePDCP entity within the DL DATA DELIVERY STATUS frame.

e) the highest transmitted PDCP Sequence Number in sequence to the MAClayer among those PDCP PDUs received from the NG-RAN node hosting thePDCP entity;

NOTE: If an E-UTRAN deployment has decided not to use the Transfer ofDownlink User Data procedure, d) above is not applicable.

The DL DATA DELIVERY STATUS frame shall also include an indicationwhether the frame is the last DL status report received in the course ofreleasing a bearer from the corresponding gNB. When receiving suchindication, if applicable, the gNB hosting the PDCP entity considersthat no more UL data is to be expected from the corresponding gNB.

The gNB hosting the PDCP entity, when receiving the DL DATA DELIVERYSTATUS frame:

-   -   regards the desired buffer size under b) and c) above as the        amount of data desired from the corresponding gNB being declared    -   from the PDCP sequence number reported under a) above within the        same frame, as well as from the most recently reported PDCP        sequence number(s) of all other data bearers established for the        UE;    -   as the momentary desired buffer sizes, independent of buffer        sizes indicated in the past.    -   is allowed to remove the buffered PDCP PDUs according to the        feedback of successfully delivered PDCP PDUs;    -   decides upon the actions necessary to take for PDCP PDUs        reported other than successfully delivered.

After being reported to the gNB hosting the PDCP entity, thecorresponding gNB removes the respective PDCP sequence numbers.

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Editor's Note: All the text below is FFS.

This frame format is defined to transfer feedback to allow the receivinggNB (i.e. gNB that hosts the PDCP entity) to control the downlink userdata flow via the sending gNB (i.e. gNB that does not host the PDCPentity).

Bits Number 7 6 5 4 3 2 1 0 of Octets PDU Type (=1) Highest HighestFinal Lost 1 PDCP PDCP Frame Packet Trans- Delivered Ind. Report mittedInd Ind Spare 1 Highest successfully delivered PDCP Sequence Number 3Desired buffer size for the data bearer 4 Minimum desired buffer sizefor the UE 4 Number of lost Xn-U Sequence Number ranges reported 1 Startof lost Xn-U Sequence Number range 6* (Number End of lost Xn-U SequenceNumber range of reported lost Xn-U SN ranges) Highest transmitted PDCPSequence Number 3 Spare extension 1-7

Figure z.5.2.2-1: DL DATA DELIVERY STATUS (PDU Type 1) Format

Editor's Note: All the text below is FFS.

Description: This parameter indicates the end of an Xn-U sequence numberrange.

Value range: {0 . . . 2²⁴−1}.

Field length: 3 octets.

Editor's Note: All the text below is FFS.

Description: This parameter indicates feedback about the in-sequencetransmitted status of PDCP PDUs at the corresponding NG-RAN node towardsthe MAC layer.

Value range: {0 . . . 2¹⁸−1}.

Field length: 3 octets.

Editor's Note: All the text below is FFS.

Description: This parameter indicates the presence of the Highestsuccessfully delivered PDCP Sequence Number.

Value range: {0=Highest successfully delivered PDCP Sequence Number notpresent, 1=Highest successfully delivered PDCP Sequence Number present}.

Field length: 1 bit.

Editor's Note: All the text below is FFS.

Description: This parameter indicates the presence of the Highesttransmitted PDCP Sequence Number.

Value range: {0=Highest transmitted PDCP Sequence Number not present,1=Highest transmitted PDCP Sequence Number present}.

Field length: 1 bit.

Editor's Note: All the text below is FFS.

Description: The spare extension field shall not be sent. The receivershould be capable of receiving a spare extension. The spare extensionshould not be interpreted by the receiver, since in later versions ofthe present document additional new fields might be added in place ofthe spare extension. The spare extension can be an integer number ofoctets carrying new fields or additional information; the maximum lengthof the spare extension field (m) depends on the PDU type.

Value range: 0-2^(m*8)−1.

Field Length: 0-m octets. For the PDU Types defined in the presentdocument m=4.

ABBREVIATIONS

At least some of the following abbreviations may be used herein. Ifthere is an inconsistency between abbreviations, preference should begiven to how it is used above. If listed multiple times below, the firstlisting should be preferred over any subsequent listing(s).

-   -   1×RTT CDMA2000 1×Radio Transmission Technology    -   3GPP 3rd Generation Partnership Project    -   5G 5th Generation    -   ABS Almost Blank Subframe    -   ARQ Automatic Repeat Request    -   AWGN Additive White Gaussian Noise    -   BCCH Broadcast Control Channel    -   BCH Broadcast Channel    -   CA Carrier Aggregation    -   CC Carrier Component    -   CCCH SDU Common Control Channel SDU    -   CDMA Code Division Multiplexing Access    -   CGI Cell Global Identifier    -   CIR Channel Impulse Response    -   CP Cyclic Prefix    -   CPICH Common Pilot Channel    -   CPICH Ec/No CPICH Received energy per chip divided by the power        density in the band    -   CQI Channel Quality information    -   C-RNTI Cell RNTI    -   CSI Channel State Information    -   CU Central Unit    -   DCCH Dedicated Control Channel    -   DC Dual Connectivity    -   DDDS Downlink Data Delivery Status    -   DL Downlink    -   DM Demodulation    -   DMRS Demodulation Reference Signal    -   DRX Discontinuous Reception    -   DTX Discontinuous Transmission    -   DTCH Dedicated Traffic Channel    -   DU Distributed Unit    -   DUT Device Under Test    -   E-CID Enhanced Cell-ID (positioning method)    -   E-SMLC Evolved-Serving Mobile Location Centre    -   ECGI Evolved CGI    -   eNB E-UTRAN NodeB    -   ePDCCH enhanced Physical Downlink Control Channel    -   E-SMLC evolved Serving Mobile Location Center    -   E-UTRA Evolved UTRA    -   E-UTRAN Evolved UTRAN    -   FDD Frequency Division Duplex    -   FFS For Further Study    -   GERAN GSM EDGE Radio Access Network    -   gNB Base station in NR (corresponding to eNB in LTE)    -   GNSS Global Navigation Satellite System    -   GSM Global System for Mobile communication    -   HARQ Hybrid Automatic Repeat Request    -   HO Handover    -   HSPA High Speed Packet Access    -   HRPD High Rate Packet Data    -   LOS Line of Sight    -   LPP LTE Positioning Protocol    -   LTE Long-Term Evolution    -   MAC Medium Access Control    -   MBMS Multimedia Broadcast Multicast Services    -   MBSFN Multimedia Broadcast multicast service Single Frequency        Network    -   MBSFN ABS MBSFN Almost Blank Subframe    -   MDT Minimization of Drive Tests    -   MIB Master Information Block    -   MME Mobility Management Entity    -   MSC Mobile Switching Center    -   NPDCCH Narrowband Physical Downlink Control Channel    -   NR New Radio (5G)    -   OCNG OFDMA Channel Noise Generator    -   OFDM Orthogonal Frequency Division Multiplexing    -   OFDMA Orthogonal Frequency Division Multiple Access    -   OSS Operations Support System    -   OTDOA Observed Time Difference of Arrival    -   O&M Operation and Maintenance    -   PBCH Physical Broadcast Channel    -   P-CCPCH Primary Common Control Physical Channel    -   PCell Primary Cell    -   PCFICH Physical Control Format Indicator Channel    -   PDCCH Physical Downlink Control Channel    -   PDCP Packet Data Convergence Protocol    -   PDP Profile Delay Profile    -   PDSCH Physical Downlink Shared Channel    -   PGW Packet Gateway    -   PHICH Physical Hybrid-ARQ Indicator Channel    -   PLMN Public Land Mobile Network    -   PMI Precoder Matrix Indicator    -   PRACH Physical Random Access Channel    -   PRS Positioning Reference Signal    -   PSS Primary Synchronization Signal    -   PUCCH Physical Uplink Control Channel    -   PUSCH Physical Uplink Shared Channel    -   RACH Random Access Channel    -   QAM Quadrature Amplitude Modulation    -   RAN Radio Access Network    -   RAT Radio Access Technology    -   RLM Radio Link Management    -   RNC Radio Network Controller    -   RNTI Radio Network Temporary Identifier    -   RRC Radio Resource Control    -   RRM Radio Resource Management    -   RS Reference Signal    -   RSCP Received Signal Code Power    -   RSRP Reference Symbol Received Power OR        -   Reference Signal Received Power    -   RSRQ Reference Signal Received Quality OR        -   Reference Symbol Received Quality    -   RSSI Received Signal Strength Indicator    -   RSTD Reference Signal Time Difference    -   SCH Synchronization Channel    -   SCell Secondary Cell    -   SDU Service Data Unit    -   SFN System Frame Number    -   SGW Serving Gateway    -   SI System Information    -   SIB System Information Block    -   SNR Signal to Noise Ratio    -   SON Self Optimized Network    -   SS Synchronization Signal    -   SSS Secondary Synchronization Signal    -   TDD Time Division Duplex    -   TDOA Time Difference of Arrival    -   TOA Time of Arrival    -   TSS Tertiary Synchronization Signal    -   TTI Transmission Time Interval    -   UE User Equipment    -   UL Uplink    -   UMTS Universal Mobile Telecommunication System    -   UP User Plane    -   USIM Universal Subscriber Identity Module    -   UTDOA Uplink Time Difference of Arrival    -   UTRA Universal Terrestrial Radio Access    -   UTRAN Universal Terrestrial Radio Access Network    -   WCDMA Wide CDMA    -   WLAN Wide Local Area Network    -   XnUP Xn interface user plane protocol

What is claimed is:
 1. A method of reporting a Downlink Data DeliveryStatus (DDDS) for a wireless terminal from a first network node to asecond network node, the method implemented by the first network nodeand comprising: generating a DDDS frame comprising: at least a firstInformation Element (IE) specifying a desired buffer size for a databearer and/or a minimum desired buffer size for the wireless terminal; afirst status indicator; and a second status indicator; determiningwhether to include a second IE in the DDDS frame, wherein the second IEspecifies a highest sequence number for a packet successfully deliveredto the wireless terminal; setting a value of the first status indicatorresponsive to the determining whether to include the second IE in theDDDS frame to indicate a presence and/or an absence of the second IE inthe DDDS frame; adding the second IE to the DDDS frame when the firststatus indicator indicates the presence of the second IE in the DDDSframe; determining whether to include a third IE in the DDDS frame,wherein the third IE specifies a highest sequence number for a packetsent to the wireless terminal; setting a value of the second statusindicator responsive to the determining whether to include the third IEto indicate a presence and/or absence of the third IE in the DDDS frame;adding the third IE to the DDDS frame when the second status indicatorindicates the presence of the third IE in the DDDS frame; and sendingthe DDDS frame to the second network node to facilitate control, by thesecond network node, of downlink data flow to the wireless terminal. 2.The method of claim 1, wherein determining whether to include the secondIE comprises determining to exclude the second IE from the DDDS framewhen the wireless terminal has not yet received data packets.
 3. Themethod of claim 1, wherein determining whether to include the second IEcomprises determining to exclude the second IE from the DDDS frame whenthe first network node has not yet received data packets from the secondnetwork node.
 4. The method of claim 1, wherein determining whether toinclude the second IE comprises determining to exclude the second IEfrom the DDDS frame responsive to determining that a current highestsequence number for a packet successfully delivered to the wirelessterminal is the same as the highest sequence number specified in apreviously sent DDDS frame.
 5. The method of claim 1, wherein the firststatus indicator further indicates the second IE in the DDDS framecomprises a dummy IE.
 6. The method of claim 1, wherein setting thevalue of the first status indicator comprises: setting the value of thefirst status indicator to “0” to indicate the presence of the second IEin the DDDS frame; and setting the value of the first status indicatorto “1” to indicate the absence of the second IE from the DDDS frame. 7.The method of claim 1, wherein the second IE specifies a highest PacketData Convergence Protocol (PDCP) Packet Data Unit (PDU) sequence numbersuccessfully delivered to the wireless terminal.
 8. The method of claim1, wherein the third IE specifies a highest Packet Data ConvergenceProtocol (PDCP) Packet Data Unit (PDU) sequence number sent to thewireless terminal.
 9. The method of claim 1, further comprising:receiving downlink data packets from the second network node via anetwork interface responsive to the sent DDDS frame; and wirelesslytransmitting the received downlink data packets to the wirelessterminal.
 10. A non-transitory computer-readable medium having storedthereon machine-readable instructions executable to cause a machine toperform operations comprising: generating a DDDS frame comprising: atleast a first Information Element (IE) specifying a desired buffer sizefor a data bearer and/or a minimum desired buffer size for a wirelessterminal; a first status indicator; and a second status indicator;determining whether to include a second IE in the DDDS frame, whereinthe second IE specifies a highest sequence number for a packetsuccessfully delivered to the wireless terminal; setting a value of thefirst status indicator responsive to the determining whether to includethe second IE in the DDDS frame to indicate a presence and/or an absenceof the second IE in the DDDS frame; adding the second IE to the DDDSframe when the first status indicator indicates the presence of thesecond IE in the DDDS frame; determining whether to include a third IEin the DDDS frame, wherein the third IE specifies a highest sequencenumber for a packet sent to the wireless terminal; setting a value ofthe second status indicator responsive to the determining whether toinclude the third IE to indicate a presence and/or absence of the thirdIE in the DDDS frame; adding the third IE to the DDDS frame when thesecond status indicator indicates the presence of the third IE in theDDDS frame; and sending the DDDS frame to a network node to facilitatecontrol, by the network node, of downlink data flow to the wirelessterminal.
 11. A first network node configured to report a Downlink DataDelivery Status (DDDS) for a wireless terminal to a second network node,the first network node comprising: one or more processing circuitsconfigured to: generate a DDDS frame comprising: at least a firstInformation Element (IE) specifying a desired buffer size for a databearer and/or a minimum desired buffer size for the wireless terminal; afirst status indicator; and a second status indicator; determine whetherto include a second IE in the DDDS frame, wherein the second IEspecifies a highest sequence number for a packet successfully deliveredto the wireless terminal; set a value of the first status indicatorresponsive to the determining to indicate a presence and/or an absenceof the second IE in the DDDS frame; add the second IE to the DDDS framewhen the first status indicator indicates the presence of the second IEin the DDDS frame; determine whether to include a third IE in the DDDSframe, wherein the third IE specifies a highest sequence number for apacket sent to the wireless terminal; set a value of the second statusindicator responsive to the determining whether to include the third IEto indicate a presence and/or absence of the third IE in the DDDS frame;add the third IE to the DDDS frame when the second status indicatorindicates the presence of the third IE in the DDDS frame; and acommunication circuit configured to send the DDDS frame to the secondnetwork node to facilitate control, by the second network node, ofdownlink data flow to the wireless terminal.
 12. The first network nodeof claim 11, wherein the one or more processing circuits determinewhether to include the second IE by determining to exclude the second IEfrom the DDDS frame when the wireless terminal has not yet received datapackets.
 13. The first network node of claim 11, wherein the one or moreprocessing circuits determine whether to include the second IE bydetermining to exclude the second IE from the DDDS frame when the firstnetwork node has not yet received data packets from the second networknode.
 14. The first network node of claim 11, wherein the one or moreprocessing circuits determine whether to include the second IE bydetermining to exclude the second IE from the DDDS frame responsive todetermining that a current highest sequence number for a packetsuccessfully delivered to the wireless terminal is the same as thehighest sequence number specified in a previously sent DDDS frame. 15.The first network node of claim 11, wherein the first status indicatorfurther indicates the second IE in the DDDS frame comprises a dummy IE.16. The first network node of claim 11, wherein the one or moreprocessing circuits set the value of the first status indicator by:setting the value of the first status indicator to “0” to indicate thepresence of the second IE in the DDDS frame; and setting the value ofthe first status indicator to “1” to indicate the absence of the secondIE from the DDDS frame.
 17. The first network node of claim 11, whereinthe second IE specifies a highest Packet Data Convergence Protocol(PDCP) Packet Data Unit (PDU) sequence number successfully delivered tothe wireless terminal.
 18. The first network node of claim 11, whereinthe third IE specifies a highest Packet Data Convergence Protocol (PDCP)Packet Data Unit (PDU) sequence number sent to the wireless terminal.